What went wrong with Biff?

I think that Biff's breaking point occurred after he failed high school math and then decided to visit his father and discovered "The Woman." Willy had always been a hero in Biff's eyes; a popular salesman that was welcomed in every town and adored by his wife and sons at home. He joked around with the boys, he encouraged Biff in football, and joked about girls with him. Like Linda once says there was never a father more loved by his sons. However, Willy taught Biff and Happy to think the most of themselves in a way that made them rebellious rather than giving them high/healthy self-esteem. Willy also thought so highly of his sons that he could not realize their faults. When Bernard warned Willy that Biff was failing math, Willy said not to worry, no one would fail Biff with all those scholarships rather than encouraging his son to try harder and study more. When Linda said Biff was getting a reputation of being to rough with the girls, Willy laughed and said that's his son. Willy pumped himself and his sons so full of confidence that when Biff discovered Willy with the girl and realized Willy was a phony, everything he had believed before became a lie. Biff became lost, floating from job to job, not taking orders from anyone but himself but having no orders to set himself straight. Biff was floundering but Willy only saw this as spite towards himself because Biff was angry at him. Biff and Willy never talked about what happened and never came to terms with it, this was their destruction. In the end Biff finally realizes he's just a "dollar an hour" kinda guy and that he is ok with that but Willy still cannot accept the truth which eventually leads to his death.